What I expected to happen was:
The subcommand "say ." is executed because the execution shouldn't depend on the number of specified entities.
What actually happened was:
The subcommand is not executed.
Steps to Reproduce:
/scoreboard objectives add test dummy
/execute store success score @r[name=] test run say .
This behavior is suboptimal because in case there is no entity for which the result is stored you have to execute the same subcommands separately from "execute store" again.